Messages in this thread Patch in this message | | | Date | Wed, 28 Sep 2022 11:40:42 -0700 | Subject | [PATCH 1/2] perf/x86/utils: fix uninitialized var in get_branch_type() | From | Stephane Eranian <> |
| |
offset is passed as a pointer and on certain call path is not set by the function. If the caller does not re-initialize offset between calls, value could be inherited between calls. Prevent this by initializing offset on each call. This impacts the code in amd_pmu_lbr_filter() which does for(i=0; ...) { ret = get_branch_type_fused(..., &offset); if (offset) lbr_entries[i].from += offset; }
Signed-off-by: Stephane Eranian <eranian@google.com> --- arch/x86/events/utils.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/x86/events/utils.c b/arch/x86/events/utils.c index 5f5617afde79..76b1f8bb0fd5 100644 --- a/arch/x86/events/utils.c +++ b/arch/x86/events/utils.c @@ -94,6 +94,10 @@ static int get_branch_type(unsigned long from, unsigned long to, int abort, u8 buf[MAX_INSN_SIZE]; int is64 = 0; + /* make sure we initialize offset */ + if (offset) + *offset = 0; + to_plm = kernel_ip(to) ? X86_BR_KERNEL : X86_BR_USER; from_plm = kernel_ip(from) ? X86_BR_KERNEL : X86_BR_USER; -- 2.37.3.998.g577e59143f-goog
| |